Ключевые слова: adapter, art, background, black, bolt, chemical, conduit, connection, construction, contour, control, element, engineering, equipment, factory, faucet, fuel, gas, gasoline, icon, illustration, industrial, industry, isolated, line, linear, lineart, metal, natural, object, oil, outline, pipe, pipeline, piping, plumbing, power, pressure, pump, sign, steel, symbol, system, tap, technology, tube, valve, water, white,